1. Field of the Invention
The present invention relates to a releasable safety device for a chair backrest. In particular, the present invention relates to a safety device that limits an inclination angle of a chair backrest, wherein the safety device can be released for transport purpose.
2. Description of the Related Art
FIG. 1 of the drawings illustrates a seat frame 10 and a backrest frame 11 for a chair of a conventional design. The seat frame 10 and the backrest frame 11 are connected together by hinges 12. Further, a stepless pneumatic positioning cylinder 13 is provided for actuating the backrest frame 11 to a desired inclined position relative to the seat frame 10 under control of a control rod 14. At least one extension 15 extends from the backrest frame 11 for limiting the inclination angle of the backrest frame 11 to be about 125 degrees, as indicated by the phantom lines in FIG. 1. This avoids falling of the user resulting from over inclination of the backrest 11. However, this safety design results in an inconvenience to transport. In particular, the leg assembly of the chair is detached from the seat for transport, but the backrest frame 11 could not be moved to a position aligned with the seat frame 10, thereby occupying a considerable space that incurs additional cost for transport.
An object of the present invention is to provide a safety device that limits an inclination angle of a chair backrest, wherein the safety device can be released for transport purpose.
A chair in accordance with the present invention comprises a seat frame and a backrest frame. A first connecting member is provided on each of two lateral sides of the seat frame. A second connecting member is provided on each of two lateral sides of the backrest frame. Each second connecting member is pivotally connected with an associated first connecting member. The inclination angle of the backrest frame relative to said seat frame is adjustable. A safety device includes a frame fixed to one of the second connecting member and a pin extending through the frame and including an end located on a path of the associated first connecting member, thereby restraining a maximum inclination angle of the backrest frame relative to the seat frame. The safety pin is movable away from the path of the associated first connecting member, allowing the backrest frame to be moved to a position aligned with the seat frame.